1. Field of the Invention
The present invention provides a feeding apparatus for monopole antennae and related analog broadcast player system and integration system, and particularly a feeding apparatus using a conduction method for transmitting signals to a monopole antenna and related analog broadcast player system and integration system
2. Description of the Prior Art
Digital broadcast satellite (DBS) is a broadcasting technique following AM and FM broadcasting. The DBS technology has better spectral utilization efficiency, and can solve the lack of available broadcasting channels. Moreover, the DBS technology also can provide CD-like quality and additional data services fitting the diversification of broadcasting media. On the other hand, the DBS has advantages of wide coverage areas, so that wherever you are (even on the ocean or in the desert), the signal of the DBS may be received. Therefore, the analog broadcasting system is tending to be replaced by the digital broadcast satellite system.
However, in general, vehicle manufacturers do not adopt the DBS receiver as a standard equipment of the head unit in order to lower costs. Thus, a user needs to buy an additional digital broadcasting demodulator for receiving digital broadcasting programs. The prior art outputs satellite broadcast programs received by the DBS receiver through the head unit of the vehicle. For example, please refer to FIG. 1. FIG. 1 is a schematic diagram of interaction between a vehicle satellite audio receiver 110 and a vehicle frequency modulation (FM) head unit 120 in the prior art. The vehicle satellite audio receiver 110 includes a satellite antenna 112, a satellite broadcast transformation device 114, and a monopole antenna 116. The vehicle FM head unit 120 includes a FM antenna 122, an FM radio receiver 124, and a speaker 126. The satellite antenna 112 is utilized for receiving a digital satellite broadcast signal S. The satellite broadcast transformation device 114 is utilized for demodulating the received digital satellite broadcast signal S into an FM signal SS—FM, and transmitting the FM signal SS—FM to the vehicle FM head unit 120 by radiating. The FM radio receiver 124 can demodulate the FM signal SS—FM into an audio signal Saudio after the FM signal SS—FM is received by the FM antenna 122. Thus, the user can output the contents of broadcast programs received by the vehicle satellite audio receiver 110 via the vehicle FM head unit 120. Nevertheless, due to the long distance between the monopole antenna 116 of the vehicle satellite audio receiver 110 and the FM antenna 122, the FM antenna 122 may receive only a slight signal after spatial propagation. In addition, because the monopole antenna 116 transmits signal energy to the FM antenna 122 by radiating, compliance to the electromagnetic compatibility and electromagnetic interference (EMC/EMI) standards of the Federal Communications Commission (FCC) should be considered. In such a condition, radiation energy cannot increase indefinitely while transmitting signals. Therefore, the transmission efficiency will become unstable above limitations.
Besides using the radiating method, the FM signal SS—FM can also be transmitted through directly connection with the vehicle FM head unit 120. However, the vehicle FM head unit 120 is integrated with a vehicle housing or interior, so the user must take the vehicle housing or interior apart and change the original wiring arrangement for connecting other signal wires, causing inconvenience for the user. In such a situation, the prior art provides another improved method that does not require taking the vehicle housing or interior apart. As shown in FIG. 2, a coaxial cable 202 having a grip 204 is substituted for the monopole antenna 116. The FM signal SS—FM is transmitted from the vehicle satellite audio receiver 110 to the vehicle FM head unit 120. The FM antenna 122 and the conducting mesh of the coaxial cable 202 are utilized for grounding. However, the exterior of the FM antenna 122 usually has an insulator, such that the conducting mesh of the coaxial cable 202 can not electrically connect to the grounding portion of the FM antenna 122, which reduces feeding characteristics.
In short, in the prior art, environmental limitations may easily cause unstable transmission when using radiation to transmit multimedia signals of other multimedia devices into a vehicle head unit. However, the user needs to take the vehicle housing or interior apart and change the original wiring arrangement to connect other types of signal wires. Therefore, development of a convenient device with good transmission efficiency becomes an important topic in this field.